Animation Flicker

Is the camera auto-exposure turned on? This is the number-one flicker culprit. Auto-exposure automatically brightens the camera image if the environment becomes dark, which is every time your hand moves in front of the camera. When the camera tries to compensate by making the image brighter, you see flicker in the frames when they're played back. Turning the auto exposure off fixes this problem.

(Here's a video which shows how to turn off a webcam's auto exposure with the AMCAP application).

Are there lights behind you? Sometimes your shadow -- which can be almost invisible in a bright room -- becomes very visible when you're taking many pictures of it, and playing the pictures back at 15 FPS. Make sure the only lights in the room are the lights shining directly on the set.

Camera Shake

When you're animating a film with toy characters, like LEGO minifigs, you want the camera to be as still as possible, or move gracefully, like a camera does in a feature film.

What NEVER looks good, is a camera image that's constantly wobbling off-kilter, as the animator bumps it with their sleeve. The best way to avoid this problem is to fasten the camera down with tape, or apply a few rubber bands, strategically.

Some animations made with larger figures, like this Paper Mario animation get away with camera shake, because the action is happening all over the room. But as a general rule, and especially if you're making shorts with minifigs and action figures, you want the camera to stay still.

Low Frame Rate

A lot of new animators post movies they've made with still-cameras. They take a lot of pictures with the camera, then use a program like Windows Movie Maker to import the images, play them back and add sound.

Turn down the volume for this one ;-). Though the filmmaker doesn't explain how the film was made, it looks similar to many films made with still cameras.

The problem with this approach is that Movie Maker (and other applications) limit the speed at which these images are played back. As of now, the fastest frame rate Movie Maker allows is 8 frames per second, (or each frame is held for a duration of 0.125).

The easiest solution to this problem is to use a frame-grabbing application, which allows you to set the frame rate to faster speeds. Pro animators typically work in the 12-24 frames per second range.

Poor Camera Angles

Most of the amateurish films I see could be improved immediately if the camera was closer to the action! Seriously. It doesn't matter how great your camera is, if it looks like the action is happening two city blocks away.

Both of these films feature characters fishing unsuccessfully, but the second is a better film because the animator used a variety of shots to tell the story.

Take your camera off the tripod, and get eye-level with your characters.

Blurry Images

Some cameras have "fixed focus", and cannot focus on objects closer than 8-12 inches. These cameras cannot be used for stop motion, since you're typically animating something that's 3-7 inches away from the lens.

Alternatively, some cameras have automatic focus. These cannot be used (unless the feature can be turned off) because the camera will repeatedly lose focus every time your hand moves into the image.

Use cameras that can focus on objects that are close to the lens, have a manual focus ring, and be prepared to adjust focus often.

No Story

Who says it takes an hour to tell a story? Here's a story in 22 seconds.

Whether your film is one minute, or one hour in length, make sure it has a beginning, a middle and an end. Stopmotion tends to get a free ride in the story department because it JUST LOOKS COOL. Audiences love watching weird stuff come to life. However, if you're serious about filmmaking, your goal should be to create stories that stand alone on their own merits.

In conclusion, the ultimate purpose of avoiding all the mistakes in this post is to make sure the quality of your animation doesn't distract from the story you're telling.